DARPA envisages robotic satellite repair missions

A former astronaut working at DARPA believes a new breed of robotics could revolutionize the satellite telecommunications industry, bringing better services to consumers and resulting in less space junk.

Pam Melroy is working on technology that could lead to robotic servicing, refueling and upgrading missions to satellites thousands of miles from earth, well beyond the range of astronauts.

“Space robotics can create a revolution,” she said in an interview with the IDG News Service on the sidelines of DARPA’s Wait, What? conference in St. Louis. Melroy is deputy director of the tactical technology office at DARPA, or the Defense Advanced Research Projects Agency, part of the U.S. Defense Department.

Her target and that of DARPA's Phoenix program is the numerous telecommunications satellites that sit 36,000 kilometers (22,000 miles) above the equator and deliver television, Internet and other services to consumers, businesses and governments around the world.

That spot, 90 times the altitude of the International Space Station, is chosen because it’s where the orbiting speed of the satellite matches that of the earth so, when viewed from the ground, the satellite always appears to be in the same place in the sky.

The advantage is satellite reception with a cheap, fixed dish, but there are several disadvantages. The satellites are almost impossible to get to and, when their life ends, they have to be blasted into a junk orbit, further polluting space.

She envisages a robotic service station that could sit in orbit and carry out upgrade, repair and refueling missions for the satellites already up there.

It’s an ambitious idea, but that’s what DARPA is all about.

Currently, telecommunications satellites last about 15 years — usually determined by the amount of fuel on board. When it runs out, the boosters that provide occasional bumps to keep it in place can no longer operate so its position cannot be controlled. That’s when they're junked.

Over that 15 year lifespan, the technology on board doesn’t change so it’s limited to whatever is state-of-the-art at the time of construction — imagine using a 15-year-old computer or cell phone — and should something break, it can’t be fixed.